Multiple auger assembly



Oct. 22, 1968 .JJ'P. WATTS 3,406,767

MULT IPLE AUG ER AS 5 EMBLY Filed Oct. 25, 1966 2 Sheets-Sheet l 23 21 INVENTOR.

JAMES P. WATTS MgM ATTORNEYS Oct. 22, 1968 Filed Oct. 25, 1966 J. P. WATTS MULT IPLE AUGER AS SEMBLY 2 Sheets-Sheet 2 INVENTOR.

JAMES P. WATTS ATTORNEYS United States Patent 3,406,767 MULTIPLE AUGER ASSEMBLY James P. Watts, 6930 E. Pinchot, Scottsdale, Ariz. 85251 Filed Oct. 25, 1966, Ser. No. 589,449 4 Claims. (Cl. 175-108) ABSTRACT OF THE DISCLOSURE -A multiple auger assembly for forming trench-like excavations between the vertical piers of a building foundation, including a substantially rectangular frame, a plurality of augers rotatably mounted within the frame, and end members carried by the frame which are contoured to engage the piers, thereby guiding the assembly during excavating operations.

This invention relates to earth drilling augers.

.More particularly, the invention concerns a multiple auger assembly which is especially adapted for excavating for building foundations.

In a further aspect, the invention relates to a device of the above type for excavating trench-like sections having vertical walls.

In a still further aspect, the invention relates to a de vice of the above type especially adapted to be guided by and excavate the earth between preset concrete piers.

In erecting large buildings which require sizeable underground foundations, it is common practice to lay out the proposed foundation line and then employ an ordinary earth drilling auger to create a series of regularly spaced cylindrical excavations. Concrete is then poured into the excavations, forming a series of underground cylindrical piers. The space between the piers is then excavated for the formation of the remainder of the foundation.

At present, the excavation between the piers is accomplished by a caisson-like device having cutting teeth, or merely a sharpened lower edge. The device is repeatedly raised by a crane and dropped rapidly between the piers, the lower cutting edge dislodging the earth which is then retained within the caisson. When the caisson is full, it is raised, swung away from the excavation, and emptied.

Various difficulties are encountered in the above practice. One difficulty is the necessary amount of prying, scraping and other formidable labor necessary to dislodge the impacted earth from the interior of the caisson. Another perplexity arises in keeping the caisson aligned between the piers as it is dropped so that it will excavate a straight line between the piers.

The previously described manner of excavating also results in a marked degree of lost time. This is evidenced by the laborious task of cleaning the caisson of the impacted soil. Further, as the caisson must be raised and then dropped .in order to perform its digging operation, the actual excavation of earth occurs only during a short portion of the working cycle.

'It would be highly advantageous, therefore, to provide a means for excavating earth between the piers which could be readily kept in alignment and conveniently purged of the earth soexcavated.

. Accordingly, it is a principal object of the present invention to provide a multiple auger assembly which, once positioned, would continuously engage and excavate the earth between the piers.

- Another object of the invention is the provision of a multiple auger assembly which is especially adapted to be guided by the piers, thereby [substantially eliminating misalignment between the piers.

A further object of the invention is the provision of the above-described multiple auger assembly which can Cir be conveniently and readily purged of the soil it has excavated.

These and other, further, and more specific objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the invention taken in conjunction with the drawings in which:

FIG. 1 is an external perspective view of a multiple auger assembly, chosen for purposes of illustration, which embodies the present invention;

FIG. 2 is a sectional View taken :along line 2-2 of FIG. 1 illustrating the arrangement of the augers and associated components of the assembly;

FIG. 3 is a partial sectional view taken along line 3-3 of FIG. 1, illustrating a preferred arrangement between the side panels and end members of the invention;

FIG. 4 is a side elevational view of the invention illustrating an alternate drive means for the angers; and

FIG. 5 is a sectional view taken along line 55 of FIG. 4 specifically detailing the vertical operative arrangement of one auger.

Briefly, in accordance with my invention, I provide a caisson-like outer frame comprising a pair of generally rectangular vertical side panels and an attached elongate, substantially horizontal top member. Attached to the ends of the frame are a pair of side members having a vertical concave outer surface to specifically engage and guide the assembly along the preset piers. The side members are attached to the edges of the end panels with a series of guide pins encompassed by springs such that the end members are free to move lateral-1y with respect to the side panels while urged in constant contact with the preset piers.

A series of earth drilling a-ugers having a central shaft and an upwardly advancing constant diameter spiral screw flight are housed within the frame. The upper end of the shaft of each auger is journaled in and protrudes through the horizontal top member of the frame. A plurality of U-shaped guides extend the vertical height of the side panels to abut the outer periphery of the screw flight of each of the augers and thus retain the a-ugers in vertical axial alignment.

Attached to the upper end of each of the shafts of the angers is a means for rotating the angers. In one pr ferred embodiment, the drive means would comprise'a chain drive sprocket attached to each of the aforementioned shafts with a continuous chain encompassingand in driving engagement with the sprockets. Extending upwardly from the central sprocket is an appropriate joint for attachment to the lower end of the drilling machine shaft which is :power rotated. Alternately, a motor airdraulic, hydraulic or electric, could be mounted to the upper horizontal member and engage a respective auger shaft.

The leading edge of the screw flight of each auger is sharpened or otherwise may contain digging teeth. Both the lower edge of the side panels and the lower edge of the end members are also sharpened.

Turning now to the drawings, in which the same reference numerals indicate corresponding elements throughout the several views, FIG. 1 is a perspective view in which a presently preferred embodiment of the invention chosen for purposes of illustration is depicted. The main frame, generally indicated by the reference numeral 10, includes a pair of spaced, parallel and generally rectangular side panels 11 and 11a having a substantially horizontal top member 12. Elongate vertical end members 13 and 13a are attached to the respective edges of the side panels 11 and 11a. A series of auger shafts 14 (the angers will be hereinafter described in detail) extend vertically upward through the horizontal top member 12. A chain drive sprocket 17 is affixed to the upper extremity of each of said auger shafts 14. Encompassing 3 and in driving engagement with each of said sprockets 17 is a continuous chain 18. The central sprocket 17 is provided with an appropriate joint 19 for attachment to the lower end of the drilling machine shaft 20. As the drilling machine shaft 20 is rotated by the drilling machine (not shown) in the direction of the arrow 21, the chain 18 is rotated in the direction of the arrow 22. Concurrently with the rotating motion as heretofore described, the drilling machine shaft 20 also exerts a downward pressure in the direction of the arrow 23.

'FIG. 2 illustrates the upwardly advancing spiral screw flight 24 as carried by each of the auger shafts 14. A series of U-shaped channel members 27 are attached to the side panels 11 and 11a. The U-shaped channel members 27 are disposed axially parallel to the auger shafts 14 in alignment with the point of tangency between the adjacent spiral screw flights 24. The channel members 27 thereby form a means for locational retention of said augers. Herein noted is the radius of curvature, generally designated by the reference character R of the external surface of the end members 13 and 13a. The radius of curvature R corresponds generally to the radius of curvature of the present piers and thereby form a means for guiding the multiple auger assembly during the excavating operation.

Turning now to FIG. 3, a presently preferred mode of attachment of the end members 13 and 13a to the side panels 11 and 11a is illustrated. An elongate shaft 28 is securely retained within the edge of the side panel 11. An elongate aperture 29 located within the end member 13 slidably communicates with the shaft 28. A counterbore 30 extends partially the outer limit of the aperture 29. A suitable spring 31 encompasses the shaft 28 and is partially housed within the counterbore 30. The spring 31 retains the end member 13 in a slightly spaced relationship from the side panel 11 and allows the end member 13 to flex laterally in the direction of the arrow 32, thereby allowing the end member 13 to compensate for any irregularities encountered in the present piers. Not herein specifically illustrated, but as will be readily apparent to those skilled in the art, a series of the above-described shaft and spring arrangements are spaced along the vertical length of the end of each of the said side panels 11 and 11a.

FIGS. 4 and 5 depict an alternately preferred drive means for use with the multiple auger assembly hereinbefore described in conjunction with the detailed description of FIGS. l-3. A suitable mounting bracket 33 is secured by bolting, welding or other appropriate manner, to the top member 12. A motor 24, which could be of the hydraulic, airdraulic or electric type, is supported by the mounting bracket 33. The motor 34 is then coupled in driving engagement with the auger shaft 14. As particularly noted in FIG. 4, the use of separate drive motors would permit alternately counter-rotating spiral screw flights.

FIG. 5 specifically illustrates certain features of either of the presently preferred embodiments. Sharpened lower edges 37 and 37a of each of the respective side panels 11 and 11a are formed by upwardly and inwardly sloping bevels 38 and 38a extending the horizontal length of the lower edge of each of said side panels 11 and 11a. A suitable bearing 39, of bronze, roller or ball type, is located by its outer race in a mating housing 40 located within the top member 12. Each of said shafts 14 is then journaled within its respective bearing 39.

In operation, the multiple 'auger assembly is first attached to the power driving shaft of an earth drilling machine. The earth drilling machine then positions the auger assembly upon the surface of the earth with respect to the proposed foundation and the preset concrete piers. The augers are now rotated by their separate drive motors or by the previously described chain drive method. As the augers rotate, their sharpened lower edges engage the earth and displaces it upwardly onto the spiral screw flight which carries the displaced earth upwardly into the interior of the frame, creating a series of adjacent cylindrical shafts bored into the earth.

Concurrent with the earth boring operation of the augers, a slight downward pressure is exerted upon the auger assembly by the earth drilling machine, whereupon the sharpened lower edges of the side and end members of the frame slice the earth to create an elongated trenchtype excavation with vertical sides. The earth dislodged by the frame is urged inwardly and becomes impacted with the earth upon the spiral screw flights of the augers. It will be readily understood by those skilled in the art that the volume of earth displaced by the frame is relatively minor.

As the auger proceeds downwardly into the earth, the concave outer surfaces of the end members abut the preset concrete piers, thus retaining the assembly in its proper operative alignment. The end members may flex laterally under spring tension to compensate for any irregularities encountered in the preset concrete piers.

When the multiple auger assembly has been displaced downwardly a distance equal to its height, it is withdrawn from the excavation by the earth drilling machine and positioned at a location remote from the excavation preparatory to discharging the contents of the assembly. Discharge of the contents is accomplished by reversing the rotational direction of the augers. This operation is highly analogous to the digging operation. The reversal of the augers causes the spiral screw flight to advance downwardly, thus discharging the impacted earth within the auger assembly. After the assembly is empty, the apparatus is re-inserted into the foundation excavation and the operation is repeated until the excavation has reached the required depth.

Various changes in the devices chosen for purposes of illustration will readily occur to persons skilled in the art. To the extent that such variations and modifications do not depart from the spirit of the invention, they are intended to be included within the scope thereof which is not limited to the devices specifically illustrated but, rather, only by a just interpretation of the following claims.

Having fully described the presently preferred embodiment of the invention in such a manner as to enable those skilled in the art to understand and practice the same, I claim:

1. A multiple earth auger assembly, particularly adapted for digging elongated trench-type building foundation excavations between vertical piers, said excavations having substantially uniform vertical sides and a generally horizontal floor and wherein the earth so excavated is retained within the assembly for subsequent disposal remote from said excavation, comprising:

(a) a frame including a pair of generally rectangular vertical side panels, a pair of vertical elongate end members, and a substantially horizontal top member; (b) a plurality of earth drilling augers disposed vertically within said frame, each said auger including a rotatable vertical shaft journaled near its upper end in the horizontal top member of said frame, and an upwardly advancing spiral screw flight carried by said shaft and having an earth engaging means at its lower terminus;

(c) means for rotating said augers within said frame,

and

(d) means associated with said end members shaped to engage said piers and guide said assembly during excavating operations.

2. The multiple auger assembly of claim 1, wherein each said vertical elongate end member includes:

(a) a longitudinally concave outer surface, and

(b) means for resiliently attaching said end member to said side panels to permit lateral movement of said end member with respect to .said side panels.

3. The multiple auger assembly of claim 1, wherein said means for rotating said augers includes:

(a) a sprocket attached to the upper end of each said auger shaft, and

(b) an endless chain in driving engagement with the said sprockets; one of said augers and its attached sprocket being driven by the power shaft of an earth drilling machine.

4. The multiple auger assembly of claim 1, wherein said means for rotating said augers comprises a plurality of driving motors, each of said motors supported by said frame and in driving engagement with one of said augers.

References Cited UNITED STATES PATENTS CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner. 

